Many portable electronic devices employ a battery package in lieu of conventional batteries or conventional battery arrangements. Existing battery packages are rechargeable and customizable, and typically include an array of rechargeable battery cells, circuitry for monitoring and regulating output power, and a casing that houses the battery cells and battery circuitry. Accordingly, battery packages can be tailored so that the battery cells meet specific power requirements, the package circuitry provides power feedback and control, and the package casing protects the package cells and circuitry from various environmental factors. For example, battery cells for portable medical equipment (e.g., defibrillators, portable X-ray devices, and insulin pumps) are designed to meet stringent power tolerances. The package circuitries for hand-held data collection devices (e.g., barcode scanners, RFID readers, and portable printers) are configured to accommodate usage patterns, and the package casings for field instruments have contact openings that are fitted with Gortex® seals to prevent moisture from entering the battery package.
Despite the foregoing advantages, battery packages are more complex than conventional batteries and can therefore be more prone to failure or diminishing performance. For example, if an individual battery cell fails, this event can cause other battery cells within the package to rapidly discharge, resulting in overheating. If the package circuitry fails, the battery package may stop functioning correctly. If the package casing becomes compromised, moisture or other types of environmental influences may affect battery package performance. Thus, to facilitate battery package operation, battery package designers need to address issues that are not common to conventional batteries and battery arrangements.